1. Field of the Invention
The present invention relates to antenna apparatus, and more particularly, to an antenna apparatus used for mobile communication units such as a portable phone and a pager.
2. Description of the Related Art
In a conventional mobile communication unit, for example, in a pager, a magnetic-current-type antenna, typical of which is a loop antenna, is used so as not to be an obstacle during operation.
Since the above-described magnetic-current-type antenna is conventionally used, however, if the distance between the antenna and the user is about 3.lambda./16, sensitivity decreases by about 5 to 6 dB, as shown in FIG. 6, and if the distance between the antenna and the user is about .lambda./4, sensitivity deteriorates by 10 dB or more. With a pager using the 280-MHz band, for example, since .lambda. is equal to about 100 cm, sensitivity decreases by about 5 to 6 dB when the distance between the antenna and the user is about 20 cm, and sensitivity deteriorates by 10 dB or more when the distance between the antenna and the user is about 25 cm. Therefore, a radio wave may not be received under certain use conditions.